Hi crew, forum newbie here, but long time electron head from the thermionic days!
Just wanted to add to this [very useful] thread that I have a 533 board with exact same issue - blown MS2582a transformer.
It looks near identical to the 534 board as pictured in the thread that mad professor has linked to.

The primary center tap is not needed on the 230v controllers - it goes nowhere, so you have a choice of two transformers.

I've had a few of these little tr's blow up in various places over the years - always shorted turns in the primary - never anything else wrong.

Will be fitting this controller up with a new 0-15 0-15 transformer. Will update here soon.